U.S. Pat. No. 4,481,700 issued Nov. 13, 1984, to Larry Redmon illustrates a panel punch and die set wherein the punch and die are connected together on opposite sides of a panel by a plurality of threaded bolts. A plurality of holes to receive the bolts must be drilled in the panel first, however. The punch and die are configured to punch a generally trapezoidal hole in the panel to receive the main body of the electrical chassis connector. However, holes for mounting screws to actually mount the connector on the panel must be drilled in separate operations following the punching operation.
A panel punch and die set that requires drilling of only one pilot hole for a draw stud extending between the punch and die is illustrated in the Greenlee Tool Company catalog August, 1985 at p. 102 and designated RS-232 panel punch. The punch shown carries a portion to punch the trapezoidal opening in the panel and also carries a pair of lateral small round punch inserts releasably attached to the punch body, one on each side of the trapezoidal opening and separate therefrom, to punch a pair of circular holes, separate from the trapezoidal opening, in the panel for receiving the mounting screws for mounting the electrical connector on the panel.
Although the panel punch shown in the catalog performs satisfactorily in service, there is a need to reduce substantially the amount of force required to effect punching with that punch and die set.